It is generally the case that a gate valve assembly that is used in a public utility distribution system is located underground. For example, in a water system the pipes typically are installed underground and thus the gate valves are also installed underground. After completion of the installation of a gate valve it is typically the case that a valve bonnet or housing is positioned over the gate valve assembly so as to protect the gate valve assembly from dirt and other contaminants and to access the operating nut to open and close the valve.
It is not unusual for these gate valve assemblies to not require significant maintenance for years. During this period of time it is not unusual for the earth strata to act upon the valve bonnet and the gate valve assembly so as to shift the bonnet relative to the gate valve assembly. When such a shifting occurs, there is a chance that the degree of misalignment between the valve bonnet and the gate valve assembly is great enough to require excavation of the earth strata about that the gate valve assembly so as to obtain access to the gate valve assembly. Obviously, the necessity of excavation is an undesirable situation.
To alleviate the potential for a misalignment to occur, there have been alignment devices that fit over the vale stem of the gate valve assembly. For example, there is a POSI-CAP® valve bonnet alignment disc that is generally circular in shape with an aperture in the center thereof. The POSI-CAP® alignment disc fits onto the gate valve assembly by sliding over the valve stem. The valve bonnet is then lowered into position over the gate valve and the POSI-CAP® alignment disc maintains the alignment between the gate valve assembly and the valve bonnet.
While the POSI-CAP® alignment disc maintains the relative alignment between the valve bonnet and the gate valve assembly, it does require that the valve nut be removed to permit the alignment disc to slide over the valve stem. It would thus be desirable to provide an alignment device that does not require the removal of the gate valve nut to connect the alignment device to the gate valve assembly.
The POSI-CAP® alignment disc does not appear to be able to accommodate valve stems of different diameters. It would therefore be desirable to provide an alignment device that can accommodate valve stems of different diameters.
In another form thereof, the invention is a gate valve assembly that comprises a gate valve stem and an alignment device for maintaining the relative alignment between a gate valve assembly and a valve bonnet when the valve bonnet is positioned over the gate valve assembly. The valve bonnet has interior surface. The alignment device comprises a pair of substantially identical components wherein the components are connectable to each other when the alignment device is attached to the gate valve assembly. Each one of the components comprises a body that has a peripheral portion. The peripheral portion is adjacent to the interior surface of the valve bonnet when the valve bonnet is positioned over the gate valve assembly. The body has a transverse edge wherein the transverse edge contains an opening that receives a part of the gate valve assembly when the components are connected together.
In yet another form, the invention is a component for connection to a substantially identical component wherein the connected components comprise an alignment device for a gate valve assembly. The component comprises a generally semi-circular body that has a peripheral portion wherein the peripheral portion is adjacent to the interior surface of the valve bonnet when the valve bonnet is positioned over the gate valve assembly. The generally semi-circular body has a diametrical edge wherein the diametrical edge contains an opening that receives a part of the gate valve assembly when the components are connected together.
In yet another form thereof, the invention is an alignment device for maintaining the relative alignment between a valve assembly that has an exposed shaft and a valve bonnet positioned over the gate valve assembly wherein the valve bonnet has an interior surface. The alignment device includes a pair of substantially identical components wherein the components are securely connectable to each other when the alignment device is attached to the gate valve assembly. Each one of the components includes a body that has a peripheral portion. The peripheral portion is adjacent to the interior surface of the valve bonnet when the valve bonnet is positioned over the gate valve assembly. The body also has a transverse edge wherein the transverse edge contains an opening. A collar defines the opening. The opening receives the exposed shaft of the gate valve assembly when the components are connected together wherein the collar is adjacent to the exposed shaft.